Various electro-optical systems have been developed for measuring dimensions of an object. One such electro-optical system is a conventional laser distance-measuring device. The laser distance-measuring device, for example, may comprise a microcontroller, a non-erasable memory, a mass memory, a keypad, a display, a radiation source, and a radiation receiver. The microcontroller controls the radiation source to emit a modulated laser beam. The laser beam is received by the radiation receiver after being reflected by a target object, and is modulated by the microcontroller. The time that the laser beam takes during the journey is recorded, and is multiplied by a propagation velocity of the laser beam to determine the distance that the device is distant from the target object. Data for the measurement is stored in the mass memory, and the result is shown on the display. In addition, operation modes and correction algorithms, which are stored in the non-erasable memory, can be selected through the keypad for desired result of the measurement.
Although the conventional laser distance-measuring device can measure a straight distance of an object from the laser distance-measuring device, it has difficulty measuring a distance between two spaced points. This measurement often is necessary in the fields of architecture and construction. For example, workers may need to measure the height of a box, a wall, a tree, or a building.
Further, in order to detect an edge or to measure dimensions of a target object, the conventional laser distance-measuring device requires a user to hold the laser distance-measuring device in his/her hands and manually aim the laser scan beam onto a target object. The user then needs to gradually move the device so that the laser scan beam sweeps across the target object. This method results in readings that may be prone to error, as an accidental movement of the hand of the user holding the device would affect the measurement of dimensions of the target object. Further, the conventional laser distance-measuring device does not automatically identify an edge of the target object. The user operating the conventional laser distance-measuring device is solely responsible for identifying the edge based on his/her judgment or view of the target object. For example, when the laser scan beam appears to have reached to an edge of the target object, the user may release a trigger switch. However, this method of identifying the edge of the target object may also be prone to human error.
Accordingly, it is desirable to have a more reliable solution for identifying an edge and measure dimensions of an object with laser distance measurement.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.